Living coral (1/3)

The coral of Hanauma Bay is home to over 450 varieties of fish, as well as
octopus, crabs and eels. This natural bay on the island of Oahu is full of a
living coral forest that grows and feeds the resident animals. The coral
formations and creatures that live there provide some of the most beautiful
underwater landscapes on the planet. The coral reefs are evidence of the area’s
natural beauty and bring thousands of visitors to Hanauma Bay every year.

What are living coral reefs?

Coral reefs are actually collections of living entities that reside under the
seawater. They are made up of individual coral organisms. Coral is an
invertebrate animal (a creature with no backbone) and belongs to the class
Anthozoa. Coral reefs are referred to as “living” because they actually are.
Many people mistake coral for rocks or other underwater objects.

Hanauma Bay is a perfect area to support a living coral reef. The area is in a
tropical sea where there is mild wave action. The curved nature of the bay
protects the coral reef from large waves that could rip it apart. The gentle
waves create enough movement in the water to circulate food and oxygen, and the
water is shallow enough to encourage coral growth.

Coral comes in two different varieties, but only one is present in Hanauma Bay.
Hermatypes are hard corals that build reefs and are seen in Hanauma. They look
like rocks and stones on the ocean floor. The other type, ahermatypes, resembles
plants and anemones.

The floor of Hanauma Bay is covered by hard coral formations, which provide
homes for fish and other creatures. Snorkelers visiting the bay glide along
above the coral bed to see the marine life.

There are many different shapes and sizes of coral, but in Hawaii there are six
dominant forms. Lobe, shelf, rice finger, cauliflower and blue corals are all
represented in the Hawaiian waters. The relatively shallow waters of Hanauma Bay
support lobe, rice blue and cauliflower corals.

All coral is made from “polyps” which are tiny animals. Polyps resemble up side
down jellyfish and they secrete a skeleton to support themselves. What we see as
coral is actually the skeletal remains of the polyps. Amazingly, the entire
ecosystem of the coral reefs of Hanauma Bay is based on these tiny creatures.